From f187f1f0cc68068c9db5109012eae278756fa54c Mon Sep 17 00:00:00 2001
From: deraadt <deraadt@openbsd.org>
Date: Thu, 18 Dec 2014 16:23:25 +0000
Subject: [PATCH] If support is present, use rdrand() at resume time.  Make the
 rdrand() function easier to call. ok reyk djm

---
 sys/arch/amd64/amd64/cpu.c | 26 +++++++++++++++++++++++---
 sys/arch/i386/i386/cpu.c   | 26 +++++++++++++++++++++++---
 2 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c
index 338b91a45aa..b76e7fc6545 100644
--- a/sys/arch/amd64/amd64/cpu.c
+++ b/sys/arch/amd64/amd64/cpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.c,v 1.75 2014/12/18 05:33:48 mlarkin Exp $	*/
+/*	$OpenBSD: cpu.c,v 1.76 2014/12/18 16:23:26 deraadt Exp $	*/
 /* $NetBSD: cpu.c,v 1.1 2003/04/26 18:39:26 fvdl Exp $ */
 
 /*-
@@ -110,6 +110,7 @@
 
 int     cpu_match(struct device *, void *, void *);
 void    cpu_attach(struct device *, struct device *, void *);
+int     cpu_activate(struct device *, int);
 void	patinit(struct cpu_info *ci);
 
 struct cpu_softc {
@@ -192,7 +193,7 @@ struct cpu_functions mp_cpu_funcs = { mp_cpu_start, NULL,
 #endif /* MULTIPROCESSOR */
 
 struct cfattach cpu_ca = {
-	sizeof(struct cpu_softc), cpu_match, cpu_attach
+	sizeof(struct cpu_softc), cpu_match, cpu_attach, NULL, cpu_activate
 };
 
 struct cfdriver cpu_cd = {
@@ -938,6 +939,7 @@ void
 rdrand(void *v)
 {
 	struct timeout *tmo = v;
+	extern int	has_rdrand;
 	union {
 		uint64_t u64;
 		uint32_t u32[2];
@@ -945,6 +947,8 @@ rdrand(void *v)
 	uint64_t valid;
 	int i;
 
+	if (has_rdrand == 0)
+		return;
 	for (i = 0; i < 2; i++) {
 		__asm volatile(
 		    "xor	%1, %1\n\t"
@@ -958,5 +962,21 @@ rdrand(void *v)
 		}
 	}
 
-	timeout_add_msec(tmo, 10);
+	if (tmo)
+		timeout_add_msec(tmo, 10);
+}
+
+int
+cpu_activate(struct device *self, int act)
+{
+	struct cpu_softc *sc = (struct cpu_softc *)self;
+
+	switch (act) {
+	case DVACT_RESUME:
+		if (sc->sc_info->ci_cpuid == 0)
+			rdrand(NULL);
+		break;
+	}
+
+	return (0);
 }
diff --git a/sys/arch/i386/i386/cpu.c b/sys/arch/i386/i386/cpu.c
index 9c99e8c0df3..3c613ca6cb7 100644
--- a/sys/arch/i386/i386/cpu.c
+++ b/sys/arch/i386/i386/cpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.c,v 1.58 2014/12/14 05:04:49 guenther Exp $	*/
+/*	$OpenBSD: cpu.c,v 1.59 2014/12/18 16:23:25 deraadt Exp $	*/
 /* $NetBSD: cpu.c,v 1.1.2.7 2000/06/26 02:04:05 sommerfeld Exp $ */
 
 /*-
@@ -107,6 +107,7 @@
 
 int     cpu_match(struct device *, void *, void *);
 void    cpu_attach(struct device *, struct device *, void *);
+int     cpu_activate(struct device *, int);
 void	patinit(struct cpu_info *ci);
 void	cpu_idle_mwait_cycle(void);
 void	cpu_init_mwait(struct device *);
@@ -155,7 +156,7 @@ cpu_init_first()
 #endif
 
 struct cfattach cpu_ca = {
-	sizeof(struct cpu_info), cpu_match, cpu_attach
+	sizeof(struct cpu_info), cpu_match, cpu_attach, NULL, cpu_activate
 };
 
 struct cfdriver cpu_cd = {
@@ -483,9 +484,12 @@ void
 rdrand(void *v)
 {
 	struct timeout *tmo = v;
+	extern int      has_rdrand;
 	uint32_t r, valid;
 	int i;
 
+	if (has_rdrand == 0)
+		return;
 	for (i = 0; i < 4; i++) {
 		__asm volatile(
 		    "xor        %1, %1\n\t"
@@ -496,7 +500,23 @@ rdrand(void *v)
 			add_true_randomness(r);
 	}
 
-	timeout_add_msec(tmo, 10);
+	if (tmo)
+		timeout_add_msec(tmo, 10);
+}
+
+int
+cpu_activate(struct device *self, int act)
+{
+	struct cpu_info *sc = (struct cpu_info *)self;
+
+	switch (act) {
+	case DVACT_RESUME:
+		if (sc->ci_cpuid == 0)
+			rdrand(NULL);
+		break;
+	}
+
+	return (0);
 }
 
 #ifdef MULTIPROCESSOR
-- 
2.20.1